Improvement in screw-presses



l. H. CLAPP.

Screw-Press.

Patented June 22,1875.

No.l64.637.

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Fl CLlV INVENT H jaw/M6 WITNESSES Ajb/Q/f Unrrnn 'ran -JAMES' H. OLAPP,OF PROVIDENCE, RHODE ISLAND.

IMPROVEMENT IN SCREW-PRESSES.

i Specification forming part'of Letters Patent No.

HGLGSY, dated June 23,1875; application filed May 6, 1875.

- have invented certain new and useful Improvements in ScrewDie-Presses, and I hereby declare that the following is a full, clear,and exact description of the same, which, with the accompanying drawingsforming part of this specication, will enable others skilled in the artto make and use the same.

Figure I is a front view of my improved screw die-press. Fig. II is aside view of the same. Fig. III is a sectional view of the concentricsleeve-stop. Fig. IV is a modification of the concentric sleeve-stop.

Similar letters of reference indicate corresponding parts.

Ihe object of this invention is to provide screw die-presses, such asare used by jewelers for stamping and embossing jewelry, with anadjustable stop, which shall act directly on the screw of the press, anduniformly concentric with the screw, so th at the die shall pass only toa certain point into the reverse part of the same, and shall be stoppedat the desired point.

The nature ot the invention consists in the I arrangement ot aconcentric stop or sleeve,

adjustable on a due-threaded screw, and acting directly on thescrew-spindle, the adjustable slides, and the peculiar construction ofthe standard.

In the drawings, Ais the nut-barrel, in which the screw-spindle turns,and which is supported by a corresponding screw-thread or nut. b is thescrew-spindle. O is the adjustable concentric stop. ,Eis a slit in thestop-sleeve C, and F a thumb-screw for securing the stopsleeve C at anydesired point. d is a ne thread out on the upper end of thescrewspindle. g g are the' slides secured to the standard, in which thecross-head reciprocates. h is an arched opening made in thestandard.

t' i is the standard. K is the lever for turning lthe screw-spindle. Lis the handle. N is the cross-head, and m the base, to which thestandard is cast.

In screw die presses used for prcssin g, punching, or embossing jewelrythe die must strike the metal with considerable force, absolutely truewith the reverse die, secured to the l base or anvil, and must bestopped at a given point, so that, while the stamped ware must be sharp,and a true counterpart of the die, no part must be cut, or any surfaceinjured by the die descending farther than is absolutely required. Inthe latter case the work is lost, and the die injured. To prevent this,and enable the operative to accurately adjust the distance to which thedie shall enter the reverse dle a tine thread, which may be cut eitherright lor left handed, but must be of a tine pitch, so that the downwardstroke ot' th e screwspindle can be irmly resisted. On this auxiliaryscrew-thread d I place the concentric sleevenut O, provided with theclamp andY thumbscrew E F.j When this sleeve-nut is turned up or downtoits proper position, and secured by the thumb-screw F, thescrew-spindle can only descend until the stop-sleeve O comes in contactwith the nut-barrel A, when the descent of the spindle is arrested. Asthe stopsleeve C is concentric with the spindle, the resistance when itis stopped is the same at all points around the screw-spindle, and theaxis of the spindle and the die remain absolutely true; whereas, inother stops heretofore used, the spindle and die are liable to unevenstrains, on account of the difficulty of adjusting such stops so astobear at all parts around the spindle alike and at the same time.

Vhen a stop is placed upon the ordinary thread of the screw-spindle, thestrain is so lgreat that an adjustable clamping device can vhardlyresist it, but when an auxiliary iner thread is used, as is shown in myinvention, the stop is easily secured, adjusted.y with great facility,and will resist all strains.

The auxiliary tine thread may be placed on which the concentricsleeve-stop may be secured, and a shoulder or boss made on the upper endof the screw-spindle, as is shownin Fig. IV, so that the shoulder willbe arrested at the proper time by the concentric stop O, and thus thesame result will be obtained.

The arrangement of the adjustable slides g g enables me to maintain atall times a more closely-tting and accurate motion of the crosshead N,as all wear can be taken up, and they can be readily adjusted exactlyparallel with die, I cut on the upper part of the screw-spin-v a tubeextending above the nut-barrel A, onl

the true line of the cross-head, thus securing greater accuracy in thework with less lateral play, and without bindingor increased friction.

V-shaped slides in such presses are liable to gum by the exposure of thelubricating-oil to the air and dust; but by making the same readilyremovable they can be easily cleaned and replaced.

The standard t' z' has an arched opening at its lower part, where itunites with the base fm. This opening h is in the rear of the dieplate,and opposite the operative when he is usingthe press.

When a strip of metal is passed laterally 'over the dies it is difcnltfor the operative to have the die always strike the exact center of thestrip, as his eyes are notin line with the center of the strip, butparallel to the same. When, however, the strip can be passed under thedie in a direction from the operative, as is done in my improved press,Where the strip-is passed through the arched opening 71 the operative isat once enabled to place the band in succession exactly under the die,and thus less work is lost, and the press can be more accurately andmore rapidly fed with one hand, andoperated with the other. Differentneighboring operatives do not interfere with one another, as is the'case when long bands are embossed on presses of the old construction.

The strength of the standard is also materially increased, thedistribution of the metal is more uniform, the casting can shrink andcool more evenly, and a stronger and more homogeneous metal, andcorrespondingly better and more durable, press is the result.

Having thus described my invention,I claim as new and desire to secureby Letters Patent- 1.l The combination of the screw-spindleb, having ascrew-thread of the usual pitch for screw die-presses, and above thesame a screw, either right or left handed, having less "pitch, with theconcentric sleeve stop C and the clamp E F, as and for the purpose setforth.

2. In combination with the screw-spindle b,

lthe nut-barrel A, the stop C, the fine screwthread d, and cross-head N,the adjustable slides g g, substantially as described.

J. H. CLAPP. Witnesses:

W. C. KING, JOSEPH A. MILLER.

